When ALP is invoked, if the full path name of the ALP executable was provided by the operating system, then the "base" portion is isolated and used to construct the value of the BaseEXE internal variable. For instance, if the user invoked ALP and the name of the executable was made available as "C:\TOOLS\ALP.EXE", then the BaseEXE internal variable would contain the value "ALP". The value of BaseEXE is used to differentiate ALP-specific components in the environment (such as data files or environment variables) from those that are globally accessible to all programs. Even multiple versions of ALP can coexist without environmental "collisions" simply by copying and renaming the ALP executable and its associated message file.
If the file name of the ALP executable is not available at run time, then the value of BaseEXE defaults to "ALP".